1. Field of the Invention
The invention relates to a power supply device which uses a piezoelectric transformer, and an electrophotographic or other type of image forming apparatus which uses the power supply device
2. Description of the Related Art
A conventional power supply device used for an electrophotographic image forming apparatus has been known (for example, Japanese Patent Application Publication No. 2006-91757), in which an output signal of a voltage-controlled oscillator (hereinafter referred to as “VCO”) controls a piezoelectric transformer capable of transforming low voltage input to a high voltage by using a resonance phenomenon of a piezoelectric vibrator thereby outputting the high voltage.